As a side note, incremental improvements have been made to the C API. For example, functions which retrieved things from tables used to be `void` before. Now, they return type information in an "int" for what they retrieve, saving a good bit of repeated performance loss from the operation (death by 10000 cuts, etc.).
My C API wrapper still doesn't take advantage of this because LuaJIT and Lua 5.1 are still so wildly popular, but maybe one day LuaJIT and friends will move onto Lua 5.3 proper and we'll have a real time to migrate to take advantage of these new APIs!